About Mole Calculator

Mole Calculator is a free set of chemistry and lab calculators. The home page works out the molar mass of any chemical formula, with the mass of every element and grams-to-moles; the other pages each solve one textbook problem: moles and mass, molarity and molality, dilutions, the gas laws, reaction amounts, pH and buffers, isotopes, heat and rates, and routine molecular biology arithmetic. Every page shows the formula it uses, the constants and unit factors, and a worked example you can repeat by hand.

The nine sections

Every calculator sits in one of nine sections, is listed in the A to Z index, and uses the atomic weights shown on the periodic table page.

What a calculator page holds

• The calculator itself, opened on a realistic example, with the answer updating as you type.
• The formula in words and symbols, with every variable and unit defined.
• The assumptions: ideal behaviour, temperature, dilute solution or complete dissociation, wherever they apply.
• A worked example that uses the example numbers step by step.
• The exact lines the calculator runs, in a “Formula used” box.

What is not here

The site does arithmetic for study and lab planning. It does not give procedures for making hazardous substances, does not cover medication, dosing or clinical preparations, and does not replace your lab method, the safety data sheet of a chemical or the instructions of your supervisor. It recommends no supplier or product. Read how the numbers are worked out.

Who runs it

molecalculator.com is an independent site. It sells nothing, carries no supplier advertising and is not affiliated with any chemical supplier, university or standards body.

Get in touch

Found a wrong result, a typo or a formula that does not fit the title? Use the contact page or write to info@molecalculator.com. Fixes are listed on the corrections page.